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tyr2005
Registered Users
Posts:10
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| 05/12/2008 8:47 PM |
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Is there any preferance to the type of hardwood floor to use over a radiant floor system. What type of wood provides a better heat mass. I have heard maentioned that Bamboo flooring is good for radiant heat, is this so?
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warmsmeallup
Registered Users
Posts:76
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| 05/13/2008 8:06 PM |
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If I had seen this entry before replying to your other question, I could have combined the responses.
If you choose to go with low voltage radiant, there are no restrictions. Since it can be nailed through anywhere on the grid, you can install any type of hardwood with no ill effects. You will need to keep some sort of humidification system in your home since radiant will not offer any and you don't want to dry out the wood.
As for which is the "best" application, there are a few factors: what is the "R" rating of the wood you choose. (the higher the "R" the longer the response time and; what wood do you like?! |
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NRT.Rob
Registered Users
Posts:360
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| 05/17/2008 11:50 AM |
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the only issue with wood is its dimensional stability.. any movement issues are exacerbated by any form of radiant. note radiant doesn't cause these issues, it just makes them worse.
a major factor determining stability is the moisture content the wood is installed at. this should be measured, and the wood should be installed at a good average moisture content for the year for your residence.
beyond that, good floating floors are better than nailed for reduced visible movement, and quartersawn wood is better than plain sawn, and narrow boards are better than wide.
Bamboo is highly variable in quality. good bamboo is good, bad bamboo is bad ;)
the radiant panel association has a good flooring guide worth reading, and it's cheap. http://www.radiantpanelassociation.org/i4a/store/category.cfm?category_id=1#Product5 |
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-=Northeast Radiant Technology=-
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warmsmeallup
Registered Users
Posts:76
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| 05/17/2008 1:27 PM |
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With exception to moisture content, as I mentioned, those factors are true with hydronic. Not with electric low voltage and certainly not with Zmesh. We have it installed under wide plank, short plank, exotics, quarter sawn, plain sawn or bamboo with no issues.
If the quality of the material is poor, that is irrelevant to the radiant system. A correctly installed radiant system must never over heat or have uneven heat paterns.
Basically, garbage in..... |
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Comfort Radiant Heating |
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NRT.Rob
Registered Users
Posts:360
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| 05/17/2008 8:49 PM |
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I disagree.
unheated floor, may be poor quality and results can be mediocre. poor quality over heated floor, however, and the results can be bad. you can see the same thing near hot water baseboard units sometimes, even when the floor itself is not heated.
If you are achieving the temperature differential under the plank required to make the top side a heating emitter, I don't see how this could be any different between electric or hydronic. note the problem is not the heating; but the heating can amplify an existing problem. If that's different for electric for some reason, then I'd have to ask how; what temperature is the element layer running at? again; anecdotal info is not helpful. we've had radiant go under all kinds of stuff "against the rules" without problems. that doesn't mean we nod our head and say 12" wide planks are great without some caveats! |
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-=Northeast Radiant Technology=-
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warmsmeallup
Registered Users
Posts:76
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| 05/18/2008 5:52 PM |
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"note the problem is not the heating; but the heating can amplify an existing problem"
Which is why I said, garbage in; gargbage out...Install poor quality flooring, get poor quality. Radiant or not.
"what temperature is the element layer running at?"
Never hotter than 85*. It's a slow growth heat that brings the plank up with the element. It maxes out at 85 at the beginning, the middle and the end of the loop. If there are no temp variations in the element, then anything you put over it will react without variation. The sun shining on a wood floor will cause more warpage or damage than low voltage Zmesh can.
We give a guaranty along with the product that it will not be the cause of any more warpage or defect than the manufacturer says the wood will have naturally.
Hydronics, by the nature of the beast, can't do that without 100' runs of pex with 100% coverage. Correct me if I'm wrong, but the water enters at one temp and exits at another. Are you saying that all the wood manufactureres are wrong when they say that it's the temperature variations in hydronics that causes the uneven expansion/contraction in their solid wood flooring, causing buckling?
We've aleady established that moisture content is important and must be handled separately. Given that, the temp variations still exist with hydronics and don't with Zmesh. |
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Comfort Radiant Heating |
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NRT.Rob
Registered Users
Posts:360
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| 05/18/2008 9:21 PM |
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the MESH itself is running at 85? Typically, that's a floor surface temperature maximum, not a bottom surface maximum, and if that were true it would indicate you are providing no more than, say, 20 BTUs/sq ft from the mat? If so, then you definitely wouldn't be straining wood floor outputs, but you must be specifying supplemental heat fairly regularly?
With hydronics, the issue is tricky, and it falls to that "reliability of install quality" arguement. A well designed system with modulated water temperatures (outdoor reset), maybe a floor sensor, should operate just fine. but there are a lot of "bang-bang", on-off fixed water temp systems and those cause a lot more expansion/contraction stress. so I would assume that is the "temperature variation" (from cold to hot, off to on) they are talking about?
Temperature drops from start to end of loops are a total non-issue, erase that from your mental lexicon. No flooring will notice the difference from that, no homeowner notices whatever difference there may be in floor temp, it doesn't limit your output much, it's really a non-issue. don't you worry about loop lengths ;)
from pipe to pipe (coverage percentage/on center distance), I've never heard of that being a problem, but then I don't design wide on center systems so I couldn't swear to it... just that I've never seen wood buckle from one pipe to the next, it's generally a larger area than that.
In short, my only experience with the problem has been either moisture related, and/or high temperature operation. Certainly with a typical on-center distance, and modulated (and appropriate!) water temps "temperature variance" would not be (and isn't) any concern I have for any wood product. |
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-=Northeast Radiant Technology=-
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warmsmeallup
Registered Users
Posts:76
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| 05/19/2008 6:08 AM |
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"With hydronics, the issue is tricky, and it falls to that "reliability of install quality" arguement."
Arguement....I fear not an arguement but an ongoing problem. But hey, they can't all be you , Rob! ;)
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Comfort Radiant Heating |
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BillN
Registered Users
Posts:30
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| 05/21/2008 11:27 AM |
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| I have only seen problems with wood flooring because of 2 reasons. The first is that the water temperature was set too high to push up the output. Or 2nd, constant circulation outdoor setback was NOT used. |
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NRT.Rob
Registered Users
Posts:360
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| 05/21/2008 11:33 AM |
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hey bill,
constant circulation is not a common choice in radiant systems. it's awesome, don't get me wrong, but saying that's a cause of the problem or a requirement isn't very helpful. it's not a viable option for most american multizone systems. |
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-=Northeast Radiant Technology=-
NRTradiant.com |
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BillN
Registered Users
Posts:30
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| 05/24/2008 12:05 PM |
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I didn't mean to rub the collective industry fur the wrong way. Why would you say that constant circilation is not viable for multizone systems? My understanding is that constant flow is better. I have had to convert many systems TO constant circulation because of problems with wood flooring, and then they worked fine. My understanding is that most wood flooring is fine with elevated temperatures, up to 85 deg surface, but what really screws with them is the changing temperature. A reset, constant flow system will typically change very slowly. A zoned system will change quickly.
Say that you have a staple up application, and the water temp is set to 140 deg. When the t-stat calls for heat at 70 room temp, say, the floor is close to 70. Then 140 deg water starts circulating. Wood is a better insulator then conductor (R1 per inch). So now the wood to water delta T is 70 deg, and the wood starts to heat up. A 70 deg rise over a length of 20 ft. across the grain will expand the wood about 3/8" (red oak assumed). I understand that its not going all the way. During this expansion, the floor can creak, groan, buckle. The floor will start to heat up. Before the floor reaches the water supply temperature the t-stat will turn off and the floor will start to cool. Then is shrinks back and this is where it tends to split. A floating floor is supposed to be good for this, but that doesn't always work.
Rob, I do understand your point that if radiant is cheaper, then you can sell more of it. Most people in my area who chose radiant, do it for comfort, not economics. But I live in a climate thats not too cold (NYC area). The norm here for new construction is forced hot air. This is because builders dont want to install radiant for a spec. house, and why should thay care about the comfort level after its sold. Most consumers don't really care that much either. As long as there is air conditioning for the 10-14 hot days in the summer, the forced hot air system used from september to may saved enough money to put in granite counter tops.
All systems that I design have outdoor reset and I attempt constant circulation. Usually there will be a lower load zone that needs to shut down (zone valve) to prevent overheating.
Also, I have used Bamboo flooring in my office. Its as good as wood as far as heat transfer goes, but its a little soft, like pine flooring. I chose it because its considered a "green" product. Bamboo is a fast growing plant in the grass family.
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NRT.Rob
Registered Users
Posts:360
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| 05/25/2008 11:05 PM |
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I use reset on almost all of my systems (except those at uber low water temps already, perhaps, where it's not really necessary). indoor and outdoor, using teknet 4 generally.
However, the vast majority of systems have a number of zones, because most people don't build houses for optimal single zone heating.
If you want TRUE constant circ for each zone, that's cost prohibitive, as well as completely unnecessary. If you design your emitter output correctly across the zones, perhaps even floor sensors which are cheap enough to add, you get very smooth operation without the expensive of a separate modulated water temp for every zone.
It's certainly not a REQUIREMENT to have constant circ. getting close is good enough in the vast majority of cases.
also, you miss my point. my systems are not "cheap" . but there is a big difference between cost effective features with real benefits and throwing a client's money out a window. as the mixing valve count climbs, that line is reached very quickly, IMHO. |
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-=Northeast Radiant Technology=-
NRTradiant.com |
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brandee
Registered Users
Posts:1
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| 05/31/2008 9:40 AM |
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| I have a question for you fiesty boys! We are planning an ICF house about 45 miles from the Greensburg diaster, which sealed the deal for the ICF guy. The house is 30'x60' with a basement under 52' and a garage connected to the nw corner offset a bit to the north and west to block the harsh winter wind. I want to use a radiant heat system in the house and garage. We need A/C from June to Sept. The basement will be stained concrete, but the main floor is my concern. I prefer a natural stone floor, probably slate. Our style is rustic, western, and we all have muddy boots so.....stone is great. We are concerned with 2 things, the weight and the decking the stone is laid on. If we use radiant on the main floor will we have some of the previously discussed issues with the decking? Since the ducts and the system will be there already should the main floor be forced air. Life has so much to offer that I really don't want to bother checking the humidity etc...on my floor, anyway you get my point. The interior walls and decking are to be steel framed and the engineer has been notified of the slate. You two guys are intriiguing so lay it all out, I want to hear it! Also, a geothermal system has been discussed, maybe a direct exchange....any ideas? |
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BillN
Registered Users
Posts:30
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| 06/02/2008 10:01 PM |
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Sorry Rob, I guess that I misunderstood you. Basically we both design systems the same way, reset water supply with zone valves. Almost constant circulation. Generally I can design a house with 1 or 2 mixed temperatures, and adjust the tubing for the desired output for each zone.
What I was refering to was a few jobs that I ran into where the plumber piped the radiant zone the same as the baseboard heat on the same system. Switching 180 deg water on and off under a wood floor created a few problems.
As far as brandee's last post, what is the question ? (I dont know where greensburg is)
Stone on the main floor is great, with radiant its even better! A finished masonry floor will need low temperatures which will make geothermal a good matchup. |
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